2020/09/30 by J. Pablo Bonilla Ataides, David K. Tuckett, Stephen D. Bartlett +2 · 3 citations
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1038/s41467-021-22274-1
published as Nat. Commun. 12, 2172 (2021) · 10+6 pages, 11 figures; v2 - minor clarifying changes; v3 - final author version. Data and code used to produce our results available at https://bitbucket.org/qecsim/qsdxzzx/. The available software extends and uses services from the quantum error correction simulation package qecsim
arxiv created 2021/04/19 · arxiv updated 2021/04/20
Performing large calculations with a quantum computer will likely require a fault-tolerant architecture based on quantum error-correcting codes. The challenge is to design practical quantum error-correcting codes that perform well against realistic noise using modest resources. Here we show that a variant of the surface code -- the XZZX code -- offers remarkable performance for fault-tolerant quantum computation. The error threshold of this code matches what can be achieved with random codes (hashing) for every single-qubit Pauli noise channel; it is the first explicit code shown to have this universal property. We present numerical evidence that the threshold even exceeds this hashing bound for an experimentally relevant range of noise parameters. Focusing on the common situation where qubit dephasing is the dominant noise, we show that this code has a practical, high-performance decoder and surpasses all previously known thresholds in the realistic setting where syndrome measurements are unreliable. We go on to demonstrate the favourable sub-threshold resource scaling that can be obtained by specialising a code to exploit structure in the noise. We show that it is possible to maintain all of these advantages when we perform fault-tolerant quantum computation.